X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/7a8cd62135619ad52e05ae1c929ef07e166e4260..8eb1dd81f53db215cf73319dc485f120addefe2d:/src/smpi/smpi_group.c

diff --git a/src/smpi/smpi_group.c b/src/smpi/smpi_group.c
index e84ed8e2dc..0222b881c3 100644
--- a/src/smpi/smpi_group.c
+++ b/src/smpi/smpi_group.c
@@ -66,7 +66,7 @@ int smpi_group_index(MPI_Group group, int rank)
 {
   int index = MPI_UNDEFINED;
 
-  if (rank < group->size) {
+  if (0 <= rank && rank < group->size) {
     index = group->rank_to_index_map[rank];
   }
   return index;